In this case, you don't negotiate a new method, you just use it. At worst,
you can use OPTIONS to learn about which methods a server might volunteer
to divulge.
The failure semantics of an unknown method are quite useful. It's hard to
make upgrades that fail-at-the-server-when-unknown. failure is an important
part of the versioning and compatibility story for dist. obj. systems.
So, to turn it around: if PEP really need semantics for requesting protocols:
"the server MUST encrypt the response or fail"
when talking to a server we weren't "sure" had PEP, or even if it had PEP, if
it had "encrypt", we'd need to invent a new method, say PGET, which would b
be dead on arrival at a non-pep server.
Instead, you use PEP to negotiate features which are not "showstoppers" and
use new methods for those which are.
Rohit Khare
Rohit Khare -- World Wide Web Consortium -- Technical Staff
w: 617/253-5884 -- f: 617/258-5999 -- h: 617/491-5030
NE43-344, MIT LCS, 545 Tech Square, Cambridge, MA 02139